Macular Hole

A macular hole is a full thickness defect of the neurosensory retina at the fovea. Idiopathic holes affect about 3 in 1000 people over 55, with incidence near 8 in 100,000 a year and a female to male ratio of 2 to 3 to 1. The mechanism is anteroposterior and tangential vitreofoveal traction from an anomalous posterior vitreous detachment.

Staging by optical coherence tomography: impending (foveal cyst or detachment), small full thickness (up to 250 micrometres), medium (250 to 400 micrometres) and large (over 400 micrometres), with or without residual vitreous attachment. Secondary causes are blunt trauma, high myopia, retinal detachment, macular telangiectasia, solar retinopathy and chronic cystoid macular edema.

Natural history: about half of impending holes resolve spontaneously. Full thickness holes close without surgery in 4 to 11%, mostly small ones. Most settle at acuity near 20/200. The fellow eye develops a hole in about 10 to 15% over 5 years, with higher risk if vitreomacular traction is present.

• Central blurring, metamorphopsia and a central scotoma
• Reading difficulty
• Acuity 20/50 to 20/400
• Fundus: round red foveal lesion about one third of a disc diameter, with yellow deposits at the base and a surrounding cuff of subretinal fluid
• Watzke-Allen sign: a thin slit beam crossing the fovea appears broken
• Red flags: trauma history, high myopia with posterior staphyloma (higher detachment risk), a recent flashes and floaters history indicating a retinal tear

• Optical coherence tomography is first line. It gives minimum linear diameter, base diameter, cuff, vitreomacular traction and the hole stage.
• Amsler grid or M-charts for metamorphopsia.
• Fundus autofluorescence shows a hyperautofluorescent window.
• Dilated peripheral retinal examination to exclude a tear.

Fluorescein angiography is rarely needed. Differentials: lamellar hole, pseudohole from an epiretinal membrane, foveal cyst, vitelliform lesion, solar maculopathy, cystoid macular edema, central serous chorioretinopathy.

Observation: impending holes and small holes with minimal symptoms, with optical coherence tomography every 4 to 8 weeks.

Surgery for symptomatic full thickness holes (ideally within 6 months):

• Pars plana vitrectomy (23 to 27 gauge) with induction of posterior vitreous detachment, peeling of the internal limiting membrane stained with brilliant blue G 0.025%, and gas tamponade.
• Gas: 20% SF6 (lasts about 2 weeks) or 14% C3F8 (lasts 6 to 8 weeks). Face down positioning for 3 to 7 days, most useful in large holes.
• Large or refractory holes (over 400 micrometres): inverted internal limiting membrane flap, free flap or autologous platelet concentrate.
• Closure rates: 90 to 95% for holes under 400 micrometres, over 90% with a flap for larger holes.

Complications: cataract (progression in about 80% of phakic eyes within 2 years), retinal tear and detachment (2 to 5%), raised intraocular pressure, endophthalmitis (about 0.05%), visual field defects, reopening of the hole.

Gas precautions: no air travel, mountain travel or nitrous oxide anesthesia until the gas is gone. Wear a wristband.

Postoperative drops: moxifloxacin 0.5% four times daily for 1 week and prednisolone 1% four times daily tapering over 4 weeks.

Follow up on day 1, week 1 and month 1, with optical coherence tomography to confirm closure. Cataract surgery follows once the hole is closed. Counsel on fellow eye symptoms and on residual metamorphopsia.